drm/nv10/gpio: fix thinko in mask for gpio lines 2-9

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv10_gpio.c b/drivers/gpu/drm/nouveau/nv10_gpio.c
index 550ad3f..9d79180 100644
--- a/drivers/gpu/drm/nouveau/nv10_gpio.c
+++ b/drivers/gpu/drm/nouveau/nv10_gpio.c
@@ -65,7 +65,7 @@
 	if (line < 10) {
 		line = (line - 2) * 4;
 		reg  = NV_PCRTC_GPIO_EXT;
-		mask = 0x00000003 << ((line - 2) * 4);
+		mask = 0x00000003;
 		data = (dir << 1) | out;
 	} else
 	if (line < 14) {